PubMed Health⌕ Search

Biomedical subjects

O Hashimoto

Publications and source records attributed to O Hashimoto.

At least 19 recordsLinked to original sources
PubMed2000

Crocus sativus lectin recognizes Man3GlcNAc in the N-glycan core structure.

Crocus sativus lectin (CSL) is one of the truly mannose-specific plant lectins that has a unique binding specificity that sets it apart from others. We studied sugar-binding specificity of CSL in detail by a solution phase method (fluorescence polarization) and three solid phase methods (flow injection, surface plasmon resonance, and microtiter plate), using a number of different glycopeptides and oligosaccharides. CSL binds the branched mannotriose structure in the N-glycan core. Substitution of the terminal Man in the Manalpha(1-3)Man branch with GlcNAc drastically decreases binding affinity much more than masking of the terminal Man in the Manalpha(1-6)Man branch. Most interestingly, the beta-Man-linked GlcNAc in N-glycan core structure contributes greatly to the binding. The effect of this GlcNAc is so strong that it can substantially offset the negative effect of substitution on the nonreducing terminal Man residues. On the other hand, the GlcNAc that is usually attached to Asn in N-glycans and the l-Fuc linked at the 6-position of the GlcNAc are irrelevant to the binding. A bisecting GlcNAc neither contributes to nor interferes with the binding. This unique binding specificity of CSL offers many possibilities of its use in analytical and preparative applications.

Animals↗
PubMed2000

Observation of a spin-flip M1 transition in 7(lambda)Li.

Using a large-acceptance germanium detector array (Hyperball), we have observed a spin-flip M1 gamma transition between the ground-state spin doublet of (7)(Lambda)Li (3/2(+)-->1/2(+)). The observed energy of 691.7+/-0.6(stat)+/-1.0(syst) keV provides crucial information on the strength of the spin-spin interaction between a Lambda and a nucleon. This is the first observation of well-identified hypernuclear gamma transitions using germanium detectors.

Journal Article↗
PubMed2000

Possible role of hepatocyte growth factor/scatter factor and activin A produced by the target organ in liver metastasis.

The molecular mechanism of organ-specific metastasis to the liver remains largely unknown. However, it is conceivable that paracrine growth factors produced by a target organ induce migration and proliferation of malignant cells to that organ, and this is the cause of organ-specific metastasis. In this study, we investigated the effect of hepatocyte growth factor/scatter factor (HGF/SF) and activin A, which are known to be produced by the liver, on the motility and growth of liver-metastatic cell line FBJ-LL. HGF/SF and activin A induced motility synergistically, but they did not affect the proliferation of FBJ-LL cells. Expression of the HGF/SF receptor, the c-met gene, and the activin-receptor type IA, type IB, and type IIA genes in FBJ-LL cells was detected by reverse transcription polymerase chain reaction. These findings suggest that both HGF/SF and activin A promote organ-specific metastasis to the liver by induction of migration through their specific receptors on liver-metastatic cells.

Activin Receptors, Type I↗
PubMed2000

Asymmetry in the nonmesonic weak decay of polarized (5)(Lambda)He hypernuclei

We have measured the asymmetric emission of protons from the nonmesonic decay of polarized (5)(Lambda)He produced by the (pi(+), K+) reaction. (5)(Lambda)He is an s-shell hypernucleus and its polarization is due to the Lambda. One expects to obtain direct information on the elementary weak Lambda-->p-->np process. The asymmetry parameter has been determined to be 0.24+/-0.22. The implication of the result is discussed.

Journal Article↗
PubMed2000

Human leukocyte antigen and season of birth in Japanese patients with schizophrenia.

OBJECTIVE: Five Japanese studies, to the authors' knowledge, without exception, have consistently shown an increased frequency of human leukocyte antigen (HLA)-DR1 in patients with schizophrenia. This suggests an association between HLA-DR1 and schizophrenia in the Japanese population. The mechanism of the association is unknown; however, prenatal infections may be involved. The present study explored factors, including winter birth, that might correlate with this mechanism. Age at onset and gender were also studied. METHOD: Factors were compared between Japanese patients with schizophrenia with and in those without HLA-DR1 (N=60 and N=307, respectively). RESULTS: A significantly higher incidence of births in February and March was observed in patients with (31.7%) than those without (15. 6%) HLA-DR1. No association was found between the presence of HLA-DR1 and other variables. CONCLUSIONS: Although this result is preliminary, it may suggest an interaction between HLA and winter birth in the development of schizophrenia in the Japanese population.

Adult↗
PubMed2000

Expression of inhibin betaA, betaB and follistatin mRNAs in the carbon tetrachloride induced rat liver regeneration model.

Follistatin (FS, an activin-binding protein) and activin A (homodimer of inhibin betaA chain) promote and inhibit cell proliferation in rat liver, respectively. The roles of activin AB (heterodimer of inhibin betaA and betaB) and activin B (homodimer of inhibin betaB) in rat liver have not been elucidated yet. In this study, we examined, by reverse-transcriptase polymerase chain reaction (RT-PCR) analysis, whether the levels of FS, inhibin betaA and betaB mRNAs change in the carbon tetrachloride induced rat liver regeneration model. The analysis was made in an hour-by-hour manner during the early stage of liver injury. There are 2 types of FS mRNA, FS-288 and FS-315, and the levels of both had begun to increase at 3 h, were maximal at 6 h, remained constant up to 12 h, and thereafter gradually decreased. The inhibin betaA mRNA had started to decline at 3 h, reached its lowest level at 6 h, partly returned at 12 h, and remained constant up to 48 h. The inhibin betaB mRNA level had begun to increase at 1 h, was maximal at 3 h, remained constant up to 24 h, and returned to the original level at 48 h. These results indicate that FS and activin A may act reciprocally in liver regeneration, and also suggest that activin AB and B may play roles in liver regeneration that differ from that of activin A.

Animals↗
PubMed1999

Analysis of carbohydrate heterogeneity in a glycoprotein using liquid chromatography/mass spectrometry and liquid chromatography with tandem mass spectrometry.

High-performance liquid chromatography with on-line electrospray ionization mass spectrometry (ESI-LC/MS) was investigated for the analysis of carbohydrate heterogeneity using RNase B as a model glycoprotein. Oligosaccharides released from RNase B with endoglycosidase H were reduced and separated on a graphitized carbon column (GCC). GCC-HPLC/MS in the positive-ion mode was successful in the identification of one Man5GlcNAc, three Man6GlcNAc, three Man7GlcNAc, three Man8GlcNAc, one Man9GlcNAc, and an oligosaccharide having six hexose units (Hex) and two N-acetylhexosamine units (HexNAc). The branch structures of the three Man7GlcNAc isomers were determined by liquid chromatography with tandem mass spectrometry (LC/MS/MS). LC/MS/MS analysis was shown to be useful for the detection and identification of a trace amount of Hex6HexNAc2 alditol as a hybrid-type oligosaccharide. Its structure was confirmed by the combination of LC/MS with enzymatic digestion using beta-galactosidase and N-acetyl-beta-glucosaminidase. The relative quantities of high-mannose-type oligosaccharides in RNase B detected by ESI-LC/MS are in reasonable agreement with those by UV, high-pH anion-exchange chromatography with pulsed amperometric detection, fluorophore-assisted carbohydrate electrophoresis. Our results indicate that LC/MS and LC/MS/MS can be utilized to elucidate the distribution of oligosaccharides and their structures, which differ in molecular weight, sugar sequence, and branch structure.

Animals↗
PubMed1999

A family with an atonic variant of paroxysmal kinesigenic choreoathetosis and hypercalcitoninemia.

We report a family with an incompletely atonic variant of paroxysmal kinesigenic choreoathetosis (PKC). Three members of the family experienced attacks of muscle weakness which resembled the choreoathetotic attacks that occur in PKC in terms of their kinesigenicity and duration, clarity of consciousness during the attacks, good therapeutic response to low doses of phenytoin, and familial transmission, but differed from choreoathetotic attacks in PKC in that they were atonic. All three affected individuals were hypercalcitoninemic.

Adult↗
PubMed1999

Renal hemodynamics in Otsuka Long-Evans Tokushima fatty rat, a model rat of spontaneous non-insulin-dependent diabetes mellitus with obesity.

Renal hemodynamic features in obese non-insulin-dependent diabetic rats remain unknown. We investigated renal hemodynamic and morphologic changes in Otsuka Long-Evans Tokushima Fatty (OLETF) rats at the age of 5 and 10 months compared with age-matched lean nondiabetic control rats (LETO). OLETF rats showed obesity compared with age-matched LETO rats. Hyperglycemia was mild in 5-month-old OLETF rats and moderate in 10-month-old OLETF rats. The absolute value for glomerular filtration rate (GFR) was significantly higher in OLETF rats than in age-matched LETO rats at the age of 5 and 10 months. Ten-month-old OLETF rats had significantly higher absolute values for renal plasma flow (RPF) than age-matched LETO rats but not 5-month-old OLETF rats. Stepwise multiple regression analysis revealed that body weight was a powerful determinant of GFR and RPF. When factored for body weight, no difference in GFR was demonstrated between 5-month-old OLETF and LETO rats, whereas 10-month-old OLETF rats still had significantly higher GFR and RPF than age-matched LETO rats. Renal hypertrophy was demonstrated in both 5- and 10-month-old OLETF rats even when factored for body weight. Glomerular volume was significantly increased in 10-month-old OLETF rats, but the ratio of glomerular volume to body weight was not different among the groups. Both absolute value for glomerular capillary length free from mesangial area and the value factored for glomerular area were significantly longer in OLETF rats than in age-matched LETO rats. Mesangial matrix expansion was remarkable in 10-month-old OLETF rats, and the glomerular sclerosis index was significantly higher in 10-month-old OLETF rats than in age-matched LETO rats. Stepwise multiple regression analysis revealed that body weight, hemoglobin A1c, and hypertriglyceridemia were powerful determinants for kidney weight and glomerular volume. These data suggest that renal hyperfiltration and hypertrophy observed in 10-month-old OLETF rats are related to diabetic metabolic disorders and that obesity-related conditions may be involved in the renal hemodynamic and morphologic features in OLETF rats.

Animals↗
PubMed1998

Highly restricted T cell repertoire shaped by a single major histocompatibility complex-peptide ligand in the presence of a single rearranged T cell receptor beta chain.

The T cell repertoire is shaped by positive and negative selection of thymocytes through the interaction of alpha/beta-T cell receptors (TCR) with self-peptides bound to self-major histocompatibility complex (MHC) molecules. However, the involvement of specific TCR-peptide contacts in positive selection remains unclear. By fixing TCR-beta chains with a single rearranged TCR-beta irrelevant to the selecting ligand, we show here that T cells selected to mature on a single MHC-peptide complex express highly restricted TCR-alpha chains in terms of Valpha usage and amino acid residue of their CDR3 loops, whereas such restriction was not observed with those selected by the same MHC with diverse sets of self-peptides including this peptide. Thus, we visualized the TCR structure required to survive positive selection directed by this single ligand. Our findings provide definitive evidence that specific recognition of self-peptides by TCR could be involved in positive selection of thymocytes.

Amino Acid Sequence↗
PubMed1998

Renal hemodynamics in rats with cadmium-induced nephropathy.

Glomerular filtration rate (GFR) is known to decline in patients with cadmium (Cd)-induced nephropathy. However renal hemodynamics in Cd-induced nephropathy remain unknown. We investigated renal hemodynamics in experimental Cd-induced nephropathy. Male Sprague-Dawley rats were given 0.18 mg/rat of cadmium chloride i.p. three times a week for 3 and 16 months. Age-matched control rats were given physiological saline. Mean arterial pressures after 3 and 16 months were identical among the groups. In comparison with age-matched control rats, significant decreases in GFR associated with a significantly lower filtration fraction (FF) were demonstrated in both groups of Cd-treated rats, but the changes were more prominent in the 16-month Cd-treated rats. Renal plasma flow was significantly decreased in the 3-month Cd-treated rats whereas it was preserved in the 16-month Cd-treated rats because of anemia. Urinary sodium excretions in both groups of Cd-treated rats were significantly greater than those in the respective control rats. On light microscopic examination, only mild degeneration of tubular cells and interstitial edema in limited areas of the proximal tubules were observed in the 3-month Cd-treated rats. In the 16-month Cd-treated rats multifocal tubular atrophy and interstitial fibrosis in the outer cortex were noted. Electron microscopic examinations revealed conspicuous degenerative changes in the proximal tubular epithelial cells, diffuse thickening of glomerular basement membranes, and foot process fusions in 16-month Cd-treated rats. These data suggested that the decline in GFR in the Cd-treated rats resulted mainly from the decline in FF, which might be functional rather than structural in origin and might be associated with proximal tubular dysfunctions.

Animals↗
PubMed1998

Increased expression of vascular endothelial growth factor is associated with tumor progression in hepatocellular carcinoma.

Vascular endothelial growth factor is a potent direct-acting angiogenic factor. Early in hepatocarcinogenesis, hepatocellular carcinomas do not show hypervascularity; at later stages, they require abundant arterial blood flow. We investigated the role of vascular endothelial growth factor in hepatocellular carcinoma arterialization. We studied 51 patients with hepatocellular carcinoma. All patients had undergone hepatic arteriography. Vascular endothelial growth factor expression was investigated by immunohistochemistry (n = 51) and in situ hybridization (n = 13), and the changes in vascular endothelial growth factor expression were evaluated in relation to tumor differentiation and changes in tumor vascularity. The expression of vascular endothelial growth factor isoforms in hepatocellular carcinomas was also analyzed by reverse transcriptase-polymerase chain reaction (n = 10). Vascular endothelial growth factor expression was detected in hepatoma cells and hepatic stellate cells, and increased vascular endothelial growth factor expression was associated with tumor dedifferentiation. Vascular endothelial growth factor expression in hypervascular hepatocellular carcinomas was greater than in those not showing hypervascularity. The major vascular endothelial growth factor isoforms expressed in hepatocellular carcinoma were 121 and 165. These findings indicate that vascular endothelial growth factors 121 and 165 play a critical role in the process of angiogenesis in hepatocellular carcinomas.

Aged↗
PubMed1998

Correlation between Bcl-X expression and B-cell hybridoma apoptosis induced by activin A.

In this study, we examined the role of bcl-XL and bcl-XS in apoptotic cell death of HS-72 cells induced by activin A. Immunoblot analysis revealed that a band of Bcl-XL was detected in HS-72 cells cultured with or without activin A. Although untreated HS-72 cells did not express Bcl-XS, the expression of Bcl-XS was significantly increased when cultured with activin A. We also investigated the expression of Bcl-XS and Bcl-XL in HS-72 cells cultured with activin A in the presence of protein kinase C inhibitor 1-(5-isoquinotinesulfonyl)-2-methylpiperazine dihydrochloride (H7), which suppressed apoptosis in HS-72 cells induced by activin A. Exposure to H7 apparently increased the level of Bcl-XL in HS-72 cells cultured with or without activin A. In contrast, no detectable band of Bcl-XS was found in HS-72 cells cultured with activin A and H7. These findings indicate that Bcl-XL upregulation and Bcl-XS downregulation induced by H7 might correlate with the suppression of activin A-induced apoptosis in B-lineage cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1998

The role of activin type I receptors in activin A-induced growth arrest and apoptosis in mouse B-cell hybridoma cells.

Activins transduce their signals by binding to activin type I receptors and activin type II receptors, both of which contain a serine/threonine kinase domain. In this study, we established stable transfectants expressing two types of activin receptors, ActRI and ActRIB, to clarify the role of these receptors in activin signalling for growth inhibition in HS-72 mouse B-cell hybridoma cells. Over-expression of ActRI suppressed activin A-induced cell-cycle arrest in the G1 phase caused by inhibition of retinoblastoma protein phosphorylation through induction of p21CIP1/WAF1, a cyclin-dependent kinase inhibitor, and subsequent apoptosis. In contrast, HS-72 clones that over-expressed ActRIB significantly facilitated activin A-induced apoptosis. These results indicate that ActRI and ActRIB are distinct from each other and that the ActRI/ActRIB expression ratio could regulate cell-cycle arrest in the G1 phase and subsequent apoptosis in HS-72 cells induced by activin A.

Activin Receptors, Type I↗
PubMed1998

Molecular cloning and expression of cynomolgus monkey interleukin-1beta cDNA.

The cynomolgus monkey cDNA encoding interleukin-1beta (IL-1beta) was molecularly cloned by the reverse transcription polymerase chain reaction from a cDNA library of adherent splenocytes stimulated with lipopolysaccharides. The sequence analysis showed that the monkey IL-1beta cDNA encodes a protein of 268 amino acids and displays a high degree (90%) of homology with the human counterpart. Substitution of amino acids resides mainly in the leader sequences of IL-1beta when compared with those of human IL-1beta. This cloned monkey IL-1beta cDNA was used to express in Escherichia coli as a fusion protein with thioredoxin and in insect cells infected with a recombinant baculovirus after molecular modification where monkey IL-1beta signal sequences were placed prior to the mature sequences of IL-1beta for efficient secretion in insect cells. Recombinant monkey IL-1beta expressed in both systems was shown to react with rabbit antihuman IL-1beta antiserum by Western blot analysis and to have the biological activity of IL-1beta in a bioassay.

Amino Acid Sequence↗
PubMed1998

Distribution of lectin binding in spermatogonia of Syrian hamsters in gonadally active and inactive states.

Lectin binding patterns in spermatogonia of Syrian hamsters in gonadally active and inactive states were examined by light and electron microscopy. After exposure to a short day cycle (SD), the testis weight and the diameter of seminiferous tubules decreased, reaching the minimum at 13 weeks. At that time, spermatogenesis was severely disrupted. In the animals kept exposed to an SD, spermatogenesis reinitiated spontaneously after 23 weeks. In the animals transferred to a long day cycle (LD) after exposure to an SD for 13 weeks, spermatogenesis reinitiated only 4 weeks later. As to the lectin binding, Dolichos biflorus agglutinin (DBA) bound specifically to spermatogonia. The number of DBA-positive spermatogonia per one seminiferous tubule increased until 13 weeks after exposure to an SD, and then gradually decreased. DBA bound to only type A spermatogonia in active testes, whereas it bound to type A, intermediate and type B spermatogonia in inactive testes. Moreover, SDS-PAGE and Western blot analysis of testes in active and inactive states indicated that DBA-binding bands (115 kDa, 76 kDa) in inactive testes were intense compared with those in active testes. The 82 kDa band was detected only in inactive testes. These results supported the finding obtained from lectin histochemistry. DBA-binding glycoprotein was detected in all types of spermatogonia in inactive testes, suggesting that this glycoprotein way concern the active/inactive state of spermatogenesis. The present study also indicated that DBA is a useful marker for spermatogonia in inactive testes of Syrian hamster.

Animals↗
PubMed1998

Serum carboxy-terminal cross-linked telopeptide of type I collagen reflects bone metastasis in hepatocellular carcinoma.

Carboxy-terminal telopeptide of type I collagen (ICTP) is a degradation product of type I collagen. In this study, we investigated the usefulness of measuring the serum ICTP concentration for diagnosing and monitoring bone metastasis from hepatocellular carcinoma (HCC). The serum concentrations of ICTP, type I procollagen carboxy-terminal propeptide (PICP), type III procollagen aminoterminal propeptide (PIIIP), type IV collagen (Ty IV), type IV collagen 7S-domain (7S), and hyaluronic acid (HA) were measured in patients with liver cirrhosis, HCC with or HCC without bone metastasis, and in healthy controls. The diagnostic efficiency of the serum ICTP and fibrosis marker levels in the HCC patients with and without bone metastasis was evaluated using receiver operating characteristic curves. We also retrospectively examined the changes in the serum ICTP levels before and after bone metastasis in the HCC patients. The serum ICTP level was significantly higher in the HCC patients with bone metastasis than in the patients with other diseases and the healthy controls. The serum PICP, PIIIP, Ty IV, 7S and HA levels of the HCC patients with bone metastasis did not differ significantly from those of the patients without bone metastasis. The diagnostic efficiency for HCC with bone metastasis was 87% for ICTP, 51% for PICP, 65% for Ty IV, 55% for PIIIP and 51% for HA. During the follow-up, the changes in the serum ICTP values paralleled the behavior of bone metastasis. These results indicate that the measurement of serum ICTP concentration is useful for detecting and monitoring HCC patients with bone metastasis.

Adult↗